com.amazonaws.serverless.proxy.spring

Class LambdaSpringApplicationInitializer

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.amazonaws.serverless.proxy.spring.LambdaSpringApplicationInitializer

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig, org.springframework.web.WebApplicationInitializer

public class LambdaSpringApplicationInitializer
extends javax.servlet.http.HttpServlet
implements org.springframework.web.WebApplicationInitializer

Custom implementation of Spring's `WebApplicationInitializer`. Uses internal variables to keep application state and creates a DispatcherServlet to handle incoming events. When the first event arrives it extracts the ServletContext and starts the Spring application. This class assumes that the implementation of `HttpServletRequest` that is passed in correctly implements the `getServletContext` method. State is kept using the `initialized` boolean variable. Each time a new event is received, the app sets the `currentResponse` private property to the value of the new `HttpServletResponse` object. This is used to intercept Spring notifications for the `ServletRequestHandledEvent` and call the flush method to release the latch.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	ERROR_NO_CONTEXT

Constructor Summary

Constructors

Constructor and Description
LambdaSpringApplicationInitializer(org.springframework.web.context.ConfigurableWebApplicationContext applicationContext) Creates a new instance of the WebApplicationInitializer

Method Summary

Modifier and Type	Method and Description
void	addListener(javax.servlet.ServletContextListener listener) Adds a new listener for the servlet context events.
void	dispatch(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Given a request and response objects, triggers the filters set in the servlet context and
org.springframework.web.servlet.DispatcherServlet	getDispatcherServlet() Gets the initialized Spring dispatcher servlet instance.
void	onStartup(javax.servlet.ServletContext servletContext)
void	service(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res)
void	setRefreshContext(boolean refreshContext)
void	setSpringProfiles(javax.servlet.ServletContext ctx, java.lang.String... springProfiles)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ERROR_NO_CONTEXT

public static final java.lang.String ERROR_NO_CONTEXT

See Also:

Constant Field Values

Constructor Detail

LambdaSpringApplicationInitializer

public LambdaSpringApplicationInitializer(org.springframework.web.context.ConfigurableWebApplicationContext applicationContext)

Creates a new instance of the WebApplicationInitializer

Parameters:

applicationContext - A custom ConfigurableWebApplicationContext to be used

Method Detail

addListener

public void addListener(javax.servlet.ServletContextListener listener)

Adds a new listener for the servlet context events. At the moment the library only emits events when the application is initialized. Because we don't have container lifecycle notifications from Lambda the `contextDestroyed` method is never called

Parameters:

listener - An implementation of `ServletContextListener`

setRefreshContext

public void setRefreshContext(boolean refreshContext)

dispatch

public void dispatch(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response)
              throws javax.servlet.ServletException,
                     java.io.IOException

Given a request and response objects, triggers the filters set in the servlet context and

Parameters:

request - The incoming request

response - The response object Spring should write to.

Throws:

javax.servlet.ServletException - When an error occurs during processing or of the request

java.io.IOException - When an error occurs while writing the response

getDispatcherServlet

public org.springframework.web.servlet.DispatcherServlet getDispatcherServlet()

Gets the initialized Spring dispatcher servlet instance.

Returns:

The Spring dispatcher servlet

setSpringProfiles

public void setSpringProfiles(javax.servlet.ServletContext ctx,
                              java.lang.String... springProfiles)
                       throws ContainerInitializationException

Throws:

ContainerInitializationException

onStartup

public void onStartup(javax.servlet.ServletContext servletContext)
               throws javax.servlet.ServletException

Specified by:

onStartup in interface org.springframework.web.WebApplicationInitializer

Throws:

javax.servlet.ServletException

service

public void service(javax.servlet.ServletRequest req,
                    javax.servlet.ServletResponse res)
             throws javax.servlet.ServletException,
                    java.io.IOException

Specified by:

service in interface javax.servlet.Servlet

Overrides:

service in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

java.io.IOException